It has conventionally done to foam-mold an electrically conductive powder such as metallic powder and carbon particles by mixing with a resin in the presence of carbon dioxide of high temperature and high pressure or supercritical state, nitrogen, etc. The surface of thus foam-molded material, however, is covered by a so-called skin structure as a resinous layer of non-cellular structure in which the electrically conductive powder is imbedded and not bared thereon, so that electrical conductivity on the surface is not enough to yield an electrically conductive molded product.
Further, it has been impossible to make the surface of molded resin porous to fill a lubricant such as oil therein.